1. Field of the Invention
The invention is related to a touch panel, and particularly, to a touch panel capable of performing various touch sensing functions.
2. Description of Related Art
At present, the touch panels can be generally classified into resistive, capacitive, optical, acoustic, and electromagnetic touch panels, wherein the resistive touch panels and the capacitive touch panels are most common.
In a resistive touch panel, the touch sensing principle is based on that two independent conductive layers contact with each other by a pressure of a single pressing point so that the two independent conductive layers are electrically connected. A sensing signal is generated at the pressing point of the resistive touch panel and a coordinate of the pressing point on the touch panel is determined according to the sensing signal. In a capacitive touch panel, the sensing principle is based on that an electric field is formed in a touch sensing electrode so that a slight change of a capacitance is generated in the touch sensing electrode when a conductive element such as a finger of a user contacts the touch sensing electrode, and a coordinate of the contacting point on the touch panel is determined according to the change of the capacitance.
The capacitive touch panel is commonly advantageous in facilitating a hand writing function and a multi touch function. Nevertheless, a restriction of the capacitive touch panel is that the user can only use the conductive element to operate the capacitive touch panel. Therefore, the user can not operate the capacitive touch panel when wearing a glove or by using a non conductive material such as a common plastic touch pen. The resistive touch panel is commonly advantageous in facilitating the operation by various materials. However, the restriction of the resistive touch panel is that it fails to have a multi touch function.